/**
 * 动态加载百度地图api函数
 * @param {String} ak  百度地图AK，必传
 */
export default function loadBMap(ak) {
  return new Promise(function(resolve, reject) {
    if (typeof window.BMap !== "undefined") {
      resolve(window.BMap);
      return true;
    }
    window.onBMapCallback = function() {
      resolve(window.BMap);
    };
    let script = document.createElement("script");
    script.type = "text/javascript";
    //http://api.map.baidu.com/api?v=2.0&ak=B9Hj5SEXA5jNEXDvt2NaHUxGIO8hhcWU
    script.src =
      "http://api.map.baidu.com/api?v=2.0&ak=" +
      ak +
      "&callback=onBMapCallback";
    script.onerror = reject;
    document.head.appendChild(script);
  });
}
